The death of an SAS trooper on active service in Sierra Leone last year ignited a legal debate, not on foreign policy, but on the often ignored question of cohabitation rights.Trooper Brad Tinnion's partner of eight years, Anna Homsi, gave birth to a daughter Georgia, just two months after his death.But Ms Homsi found out that, because they were not married, she was not entitled to a full widow's pension under regulations dating back to 1884.Her threats to sue the Ministry of Defence (MoD) for full pension rights, which could amount to £18,000 a year, come at a time when the legal profession's two main family law bodies have urged changes to the cohabitation laws and attempts have been made to introduce legislation in Parliament.Britain is lagging behind its European neighbours including France, Holland, several of the Scandinavian countries, and also some Australian states, in failing to recognise such rights for both heterosexual and homosexual couples.The fact is that despite the bandying around of terms such as common law partner, a person may live with another for decades without ever gaining any concrete rights as regards property, trusts, pensions and so on.

A cohabitee is seldom recognised in law at present.The view of most family law practitioners is summed up by Nigel Shepherd, a past chairman of the Solicitors Family Law Association (SFLA) and partner in the Manchester office of Addleshaw Booth & Co.He says: 'Almost everybo dy is agreed that some kind of law change is required, as at the moment it is both out of kilter with what the public thinks the law is, and how it views the subject.'All too often cohabitees only find out the legal realities when disaster comes in the form of a relationship breakdown or death, and any possible redress arrives only after much graft and ingenuity from their lawyers.James Copson, a partner at City firm Withers, claims that a claimant cohabitee is left having to delve into a complex web of trusts and property law.He notes: 'What is happening is that we are having to rummage round in the dusty corners of these branches of law in order to achieve results for people in difficult situations.'Mr Copson adds that this can end up with searches through old receipts and bank statements to prove that the claimant party has made contributions to a property, on the deeds and mortgage of which their name will not appear.The major problem alongside the fact that cohabitees have next to no legal standing, is that they also are not accorded 'the fairness outcome', which is recognised as the due of those in a marriage who suffer a bereavement or breakdown.Recognising the deficiencies that currently exist, both the SFLA and the Law Society's family law committee have produced papers calling for legislative change.The SFLA set out its position a year ago with 'Fairness for Families' -- if a person lives with another for two years and there exists a personal relationship or a financial commitment, or if there are children in the relationship, then they are entitled to claim relief on the breakdown.The family law committee is currently taking soundings from a range of relevant other committees prior to creating draft legislation for publication next year.Committee chairman Peter Watson-Lee says it believes that there should be protection for those in long-term relationships whose partners suddenly disappear, leaving their costly responsibilities behind.The family law committee has produced similar recommendations in recent years, and both organisations remain resolute that change has to happen.

But at the same time lawyers do not necessarily suggest that a cohabitation relationship should gain the full rights of a marriage.Mr Shepherd says: 'Marriage is an important institution that people choose to go into and that should be recognised.'Campaigners for change also realise that opposition can be expected from church groups keen to maintain the sanctity of marriage and its claimed superiority to cohabitation.The specialist family groups have found allies in Parliament; two Bills, one in each house, are under discussion this autumn.Liberal Democrat peer Lord Lester of Herne Hill QC is introducing a private member's Bill on the issue and a similar proposal has recently been made in the Commons by Labour backbencher Jane Griffiths.Her Relationships (Civil Registration) Bill was given an airing on the floor of the House last month, though as a ten-minute rule Bill it is unlikely to become law despite being given a second reading.The Bill aims to give couples who undergo a civil registration all the rights of a married couple.The Law Society and specialist associations back the Bill as a way of giving the subject publicity, but with reservations.

To gain equal treatment, participants must actively opt into the scheme, a method disliked by many family specialists.Mr Copson says: 'This type of scheme creates a two-tier hierarchy, because if you are not conversant with the law you end up with second-class treatment .'All parties agree that the necessary legal change can only come about through government-backed legislation, as judicial interpretation of case law cannot set cast-iron precedents.

However, despite paying the occasional lip service, the matter appears low on the list of government priorities.Both the Human Rights Act (HRA) and the Greater London Authority's partnership register have added to the pressure.The register -- launched this autumn -- is intended as a way of publicly stating a couple's commitment to one another, whether they are heterosexual or homosexual.The ceremony is symbolic, but advocates of change recognise its publicity value as an aid to moving the debate on.As for the HRA, it has yet to be tested in relation to this issue, but supporters believe with its various commitments to individual rights and family life it might yet come in handy.But it is not one that is currently being considered by Anna Homsi's solicitor Tom Reah -- a partner with Harrogate firm Powell Edison Freeman & Wilks -- who believes that course will only lead to a five-year trek through the courts.After Ms Homsi threatened to sue the MoD to gain her war widow pension rights, the MoD awarded a £20,000 payment and a £2,000-a-year allowance until the baby reaches 17 years-old.

After she sought legal advice, the ministry added the offer of an ex gratia payment of £250,000.Mr Reah said the offer was currently under consideration.

But actuarial research done on behalf of his firm revealed that a full widow's pension could yield double the payment on offer.Since becoming involved in the case, Mr Reah has been contacted by several people all in the same position as his client.

This has confirmed his view that change is needed.He states: 'A lot of people get married and divorced, or simply choose to live apart and as far as the law is concerned such widows get pensions from their husbands even if they've not been near each other for years.'The MoD is currently reviewing its pensions policy and there is a hope that the public sector in general will follow the lead of many private companies, which accord cohabitees the same pension rights as spouses.Ms Homsi's case, together with the other pressures, may yet yield change from politicians.

Significantly, they voted this year to amend their own pension scheme to provide unmarried partners with a pension.